How to check default color depth of default image on STM32MP157C/F -DK2

[Dat Tran]

On the default image provided from ST, is there any way to check what color depth is running on it.

I think it is 24bit but not sure. I ran modetest but no option to show this information.

[OlivierK]

Hi Dat Tran (Community Member) 

Do you refer to splash_landscape.bmp? or something else?

$ mediainfo splash_landscape.bmp | grep 'Bit depth'

Bit depth                : 8 bits

[OlivierK]

Hi Dat Tran (Community Member)

Any updates?

Thx

Olivier

[Dat Tran]

Hi @OlivierK​ 

Sorry because "Image" made you think the bitmap image, my image means the img file that write to raw SD.

I mean how to check hardware. I still can't find any solution yet, but we decided to go with 16 bit.

My question is something like, on Window, we can select Display - Setting property .... and we know the display is working on 32bit or 24 bit...

But I could not find anything similar in linux with command line.

I check framebuffer it is 16bit, it doesn't mean Linux is running 16bit.

[OlivierK]

Hi Dat Tran (Community Member)

Sorry your request is still not crystal clear to me.

Do you ask for the graphical framework color deph embedded by default in ST built image, which is the GTK framework for instance. ?

[OlivierK · Accepted solution]

Hi Dat Tran (Community Member)

You may have the information you need in https://wiki.st.com/stm32mpu/wiki/DRM_KMS_overview

Color format supported using the standard OSTL DV4 on DK board image

at GPU output -> LTDC input

root@stm32mp1:~# modetest -M stm

...

        in_formats blob decoded:                                    

             AR24: LINEAR                                     

             XR24: LINEAR                                     

             RG24: LINEAR                                     

             RG16: LINEAR                                     

             AR15: LINEAR                                     

             XR15: LINEAR                                     

             AR12: LINEAR                                     

             XR12: LINEAR                                     

             C8 : LINEAR  

root@stm32mp1:~# cat /sys/kernel/debug/dri/0/state  

format=XR24 little-endian (0x34325258)   -> 24-bit color depth.

Rgds,

Olivier